BEHAVIOR Challenge 2026 — joint tasks 56/78/99 (make_rose_centerpieces, make_cabinet_doors, sorting_books_on_shelf), fine-tune ft1, step 19999
Selected checkpoint for the BEHAVIOR-1K 2026 submission.
Model
- Architecture: the 2025 BEHAVIOR Challenge winner's pi0.5-based policy
(IliaLarchenko/behavior-1k-solution, ~3B params, task-ID embeddings, no language prompt).
- Init: the winner's 50-task generalist checkpoint (
IliaLarchenko/behavior_50t_checkpoint); 100 task slots.
- Training config:
pi_behavior_b1k_2026_3more (in our pipeline repo's behavior-1k-solution/src/b1k/training/config.py).
- Data: 2026 challenge demos, 2026 demos for tasks 56, 78 and 99 combined, RGB cameras only.
- Recipe: 20,000 steps (final step is 19999), 1x A100 80GB. Final training loss ~0.21.
- Checkpoint is params-only (no optimizer state): it can be served or used as an init, not
--resumed.
Layout
params/ — orbax/ocdbt parameters
assets/b1k_2026_3more_tasks/norm_stats.json — normalization stats
_CHECKPOINT_METADATA
Serve with scripts/serve_b1k.py --task-id 56 policy:checkpoint --policy.config pi_behavior_b1k_2026_3more --policy.dir <this dir> (use --task-id 78 for task 78).
Evaluation (local; q = fraction of goal predicates newly satisfied)
Scored the 2026 leaderboard way: public instances 0-9 (ids 301-310), one rollout each, default 1.5x
timeouts, task score = sum / 10.
Task 56 (4 goal predicates)
Leaderboard score: q = 0.35 (sum 3.5 over 301-310; full completions: none)
| instance |
301 |
302 |
303 |
304 |
305 |
306 |
307 |
308 |
309 |
310 |
| q |
0.5 |
0 |
0 |
0.25 |
0.25 |
0.25 |
0.5 |
0.5 |
0.75 |
0.5 |
Task 78 (single attached goal, all-or-nothing)
Leaderboard score: q = 0 (sum 0 over 301-310; full completions: none)
| instance |
301 |
302 |
303 |
304 |
305 |
306 |
307 |
308 |
309 |
310 |
| q |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
- Use this checkpoint for tasks 56 and 78. For task 99 use the dedicated retrain
Rena-Tian/b1k-2026-task99-ft1 (0.0364 vs 0.0182 here).
- Step 8000 of this run scored 0 on its task 56 screen, so the final step was kept.